This invention relates to motorized wheels for 5 wheelchairs and other light vehicles, of the type in which an electric motor is built into the wheel hub, and to systems for the control of such wheels
U.S. Pat. No. 5,246,082 (Alber) discloses a motorized wheel for wheelchairs and the like, in which the wheel is designed to plug into a special socket on the wheelchair, and a hub against which the motor reacts is fixed relative to the frame by an arm, radially displaced from the axis of the hub, which fixes the hub to the frame of the chair U.S. Pat. No. 5,199,520 (Chen) discloses a wheelchair with motorized wheels, in which the wheel hubs are permanently secured to the frame of the chair, and the wheels are removable from the hubs.
Both of these arrangements permit the wheels of a wheelchair or other vehicle to be removed when the vehicle is folded or otherwise prepared for transportation, but, in each case, the vehicle must be specially adapted for this purpose, and the wheels are not directly applicable to a wheelchair or other vehicle of which the hub""s driving wheels are secured in tubular journals incorporated in the frame of the vehicles. Moreover, more effective and efficient control of the motors in the prior art arrangements in order to minimize electricity consumption and provide optimum assistance to a user or driver of the vehicle would be desirable. It is also important that a motorized wheel designed for application to vehicles originally designed for human propulsion does not overstress the frame of the vehicle.
It is an object of the invention to provide a motorized wheel and controls there for which can be applied to a vehicle, which can be readily removed from the vehicle, which is less likely to apply excessive stresses to the frame of the vehicle, and which permits improved control of the motor of the wheel.
According to the present invention in a first aspect, a motorized wheel for a vehicle has a hub portion, a drum supporting a rim and tire for rotation relative to the hub, the drum and hub having a common axis, the hub itself being rotatable about the common axis, a shaft by which the hub portion is mounted for pivotal motion on its axis relative to a frame of the vehicle, and a bracket mounted on the hub portion or shaft spaced from the axis, the bracket being disposed to engage a frame member of the vehicle to limit pivotal motion of the hub relative to the frame of the vehicle, the engagement being through a torque sensing device which generates signals indicative of the direction and magnitude of reaction forces between the bracket and the frame, a motor mounted within the hub portion and in driving connection with the drum portion, and a control device for the motor receiving the signals and applying feedback control to the motor according to the torque reaction developed between the wheel and the frame.
According to the present invention in a second aspect, a motorized wheel for a vehicle has a drum portion supporting a wheel rim, and a hub portion housing a drive motor within the drum in driving connection with the drum portion, the drum portion being mounted for rotational movement relative to an axis of the hub portion, which is mounted by a shaft to the vehicle, mounting of the drum portion on the hub portion being by means of plural roller bearings supported by the hub portion spaced around a periphery of the drum portion.
The invention also extends to a vehicle including at least one motorized driving wheel having a drum portion supporting a wheel rim, and a hub portion supporting a motor in driving connection with the drum portion, the drum portion being rotatable about the hub portion, a sensor sensing magnitude and direction of reaction forces applied to the hub by the rim portion and the motor, a battery for powering the vehicle, and a control unit receiving input from said sensor and a driver-operated control, the signals from the sensor being used to control the torque developed by the motor.